Pump a Grump

To Pump a Grump, is to take a massive shit.

I ate 12 tacos, and that night i had to pump a grump.

by Nick Wolff June 18, 2006

pump a grumper

to take a huge hard dump

damn im never gonna hti a mexican buffet liek that again, i had to pump a grumper really bad ten minutes later

by collinD May 30, 2006